Racks for high-temperature metal processing

ABSTRACT

In various embodiments, apparatuses for receiving and supporting one or more components during processing thereof at process temperatures greater than approximately 1000° C. feature refractory metal shelves separated by refractory metal support posts.

RELATED APPLICATION

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 62/117,192, filed Feb. 17, 2015, the entiredisclosure of which is hereby incorporated herein by reference.

TECHNICAL FIELD

In various embodiments, the present invention relates to supportstructures for high-temperature processing.

BACKGROUND

While high-temperature metal fabrication and joining processes are usedin many different industries and to generate a host of differentmetallic parts, the extreme temperatures of such processes place manydemands on the processing spaces and support structures utilized duringprocessing. The joining of metal parts via high-temperature brazing(i.e., the joining of materials via a joint composed of a brazingmaterial) is one such example, as the support structure on which theparts rest during processing must be able to tolerate vacuum or reducingambients and extreme temperatures (e.g., greater than 1000° C.) withoutdeformation or failure.

Conventional support structures for brazing processes include rack-likestructures fastened together via welding or riveting, but suchstructures are typically unsuited for the extreme environments utilizedin high-temperature brazing processes. Specifically, the materials ofwhich such structures are composed may deform or fail when supportingheavy loads (i.e., the parts being brazed, which may weigh hundreds ofkilograms or more) at extreme temperatures. Conventional supportstructures may deform under such conditions by, e.g., creep, and disturbthe parts being brazed or even fail entirely, resulting in economic lossand reduced productivity. Thus, there is a need for improved structurescapable of supporting heavy loads during high-temperature processeswithout deformation, failure, or reaction with processing ambients ormetallic parts being processed.

SUMMARY

In accordance with various embodiments of the present invention, supportracks for high-temperature processing (e.g., brazing, dewaxing, or thelike) are formed of a series of plates (or “shelves”) supported andseparated from each other by threaded posts incorporating supportcollars for improved stability. In various embodiments, the bottom endof the post is threaded and engages with a complementarily threaded holein the shelf below, while the top end of the post includes a supportcollar for supporting the shelf above. In various other embodiments, theupper end of the post is threaded and incorporates a support collar. Insuch embodiments, the upper threaded end engages with a complementarilythreaded nut featuring a tapered recess defined by the upper surfacethereof. This recess receives the lower end of the post, which istapered to snugly fit within the nut recess. Since in some embodiments aset of posts is only threadingly fastened to one shelf (either the shelfabove or below the posts), one or more of the shelves may include one ormore (and preferably two or more, e.g., four) “lift hooks” enabling themodularized movement, assembly, or disassembly of the full rack onemodule (i.e., a shelf with all associated posts) at a time, dependingupon the demands of a particular high-temperature process. In variousembodiments, the rack may also incorporate one or more support layers onwhich the various shelves and posts are disposed. The support layer(s)may include or consist essentially of a series of bars or braces thatsupport the weight of the rack while reducing the amount of arealcontact between the bottom surface of the rack and the high-temperaturefurnace (or other processing equipment) compared to an embodiment inwhich one of the shelves themselves were to rest directly upon thefurnace surface.

One or more of the parts of the racks include, consist essentially of,or consist of one or more refractory materials (e.g., refractory metals)having melting points higher than the temperatures utilized forhigh-temperature brazing processes (e.g., 1000° C.-1100° C.). In variousembodiments, one or more of the rack parts include, consist essentiallyof, or consist of one or more TZM alloys (i.e., alloys of titanium (Ti),zirconium (Zr), and molybdenum (Mo), with optional additions of carbon(C)), as such alloys exhibit superior resistance to creep whensupporting heavy loads at extreme temperatures (e.g., 1000° C.-1400° C.)and thus resist deformation (and resulting failure) at suchtemperatures. In various other embodiments, one or more of the rackparts include, consist essentially of, or consist of one or morerefractory metals, e.g., niobium (Nb), tantalum (Ta), rhenium (Re),tungsten (W), and/or Mo. In various embodiments, one or more of the rackparts incorporate one or more alloying elements, for example lanthanum(La), at concentrations of, e.g., approximately 0.01% to approximately1%.

In various embodiments of the invention, the shelves of the rack areperforated (i.e., a series of apertures is defined therethrough) inorder to allow gas to flow through the shelves during processing. Suchgases may include, for example, the by-products of out-gassing of theparts or the brazing material during processing, or process gases (e.g.,hydrogen and/or another appropriate process gas) utilized to generate adesired processing atmosphere (e.g., a reducing atmosphere), i.e., theprocessing “ambient.” While racks in accordance with embodiments of thepresent invention may include any number of shelves, typicalimplementations include two, three, or even more shelves with theaforementioned threaded posts disposed therebetween and supporting thelayered shelves. In various embodiments, the support post upon which thetop shelf rests is configured to penetrate through the top shelf. Thisprotruding section of the upper support post may define a lateralaperture through which a locking pin may be disposed to lock the uppershelf in place. In various embodiments, the locking pin is held in placeby one or more retaining wires. Alternatively, a threaded cap or nut mayalso be used to lock the upper shelf in place.

In an aspect, embodiments of the invention feature an apparatus forreceiving and supporting one or more components during processingthereof at a process temperature greater than approximately 1000° C. Theapparatus includes or consists essentially of a first shelf, a pluralityof first support posts, and a second shelf. The first shelf includes,consists essentially of, or consists of a first refractory metal havinga melting point greater than the process temperature. The first shelfdefines therein or therethrough a plurality of apertures, each aperturebeing threaded through at least a portion of its thickness. One or moreof the first support posts includes, consists essentially of, orconsists of a second refractory metal having a melting point greaterthan the process temperature. One or more of the first support posts hasa threaded lower end for engagement with a threaded aperture of thefirst shelf. One or more of the first support posts defines a supportcollar proximate an upper end opposite the threaded lower end. A lateraldimension (e.g., a width or diameter) of the first support post abovethe support collar is smaller than a lateral dimension (e.g., a width ordiameter) of the first support post below the support collar. The secondshelf includes, consists essentially of, or consists of a thirdrefractory metal having a melting point greater than the processtemperature. The second shelf defines therein or therethrough aplurality of apertures. One or more apertures of the second shelfreceives and/or is configured to receive the upper end of one of thelower support posts such that a portion of the second shelf proximateeach aperture thereof rests upon the support collar of the first supportpost received in the aperture.

Embodiments of the invention may include one or more of the following inany of a variety of combinations. One or more of the components may be ametallic part. The apparatus may resist creep deformation at the processtemperature. The first, second, and/or third refractory metals mayinclude, consist essentially of, or consist of a TZM alloy. The TZMalloy may include, consist essentially of, or consist of approximately0.40-approximately 0.55 weight percent Ti, approximately0.06-approximately 0.12 weight percent Zr, and the balance Mo. The TZMalloy may include, consist essentially of, or consist of approximately0.50 weight percent Ti, approximately 0.08 weight percent Zr, and thebalance Mo. The first, second, and/or third refractory metals mayinclude, consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo.The first shelf and/or the second shelf may define a plurality ofperforations therethrough. The threaded lower end of each of the firstsupport posts may include a support shoulder defined therein. Theapparatus may include a third shelf and a plurality of second supportposts. The third shelf may include, consist essentially of, or consistof a fourth refractory metal having a melting point greater than theprocess temperature. The third shelf may define therein or therethrougha plurality of apertures. One or more of the second support posts mayinclude, consist essentially of, or consist of a fifth refractory metalhaving a melting point greater than the process temperature. One or moreof the second support posts may have a threaded lower end for engagementwith a threaded aperture. One or more of the second support posts maydefine a support collar proximate an upper end opposite the threadedlower end. A lateral dimension (e.g., a width or diameter) of the secondsupport post above the support collar may be smaller than a lateraldimension (e.g., a width or diameter) of the second support post belowthe support collar. One or more of the second support posts may define adowel pin mount through the upper end thereof above the support collar.The upper end of one or more of the second support posts is receivableand/or received within an aperture of the third shelf such that (i) aportion of the third shelf proximate each aperture thereof rests uponthe support collar of the second support post received in the aperture,and (ii) the dowel pin mount of the second support post is disposedabove a top surface of the third shelf. The fourth and/or fifthrefractory metals may include, consist essentially of, or consist of aTZM alloy. The TZM alloy may include, consist essentially of, or consistof approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The fourth and/or fifth refractory metals mayinclude, consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo.

The threaded lower end of one or more of the second support posts mayinclude a support shoulder defined therein. The third shelf may define aplurality of perforations therethrough. The apparatus may include aplurality of locking pins. One or more of the locking pins may include,consist essentially of, or consist of a sixth refractory metal having amelting point greater than the process temperature. One or more of thelocking pins may be receivable and/or received within a dowel pin mountof a second support post, thereby preventing disengagement of the secondsupport posts from the third shelf. The sixth refractory metal mayinclude, consist essentially of, or consist of a TZM alloy. The TZMalloy may include, consist essentially of, or consist of approximately0.40-approximately 0.55 weight percent Ti, approximately0.06-approximately 0.12 weight percent Zr, and the balance Mo. The TZMalloy may include, consist essentially of, or consist of approximately0.50 weight percent Ti, approximately 0.08 weight percent Zr, and thebalance Mo. The sixth refractory metal may include, consist essentiallyof, or consist of Nb, Ta, Re, W, and/or Mo. One or more of the lockingpins may define one or more apertures therethrough.

The apparatus may include a plurality of retaining wires. One or more ofthe retaining wires may include, consist essentially of, or consist of aseventh refractory metal having a melting point greater than the processtemperature. One or more of the retaining wires may be receivable and/orreceived within an aperture of a locking pin, thereby preventingdisengagement of the locking pin from the second support post in whichit is received or receivable. The seventh refractory metal may include,consist essentially of, or consist of a TZM alloy. The TZM alloy mayinclude, consist essentially of, or consist of approximately0.40-approximately 0.55 weight percent Ti, approximately0.06-approximately 0.12 weight percent Zr, and the balance Mo. The TZMalloy may include, consist essentially of, or consist of approximately0.50 weight percent Ti, approximately 0.08 weight percent Zr, and thebalance Mo. The seventh refractory metal may include, consistessentially of, or consist of Nb, Ta, Re, W, and/or Mo. Two or more (inany combination), or even all, of the first, second, third, fourth,fifth, sixth, and seventh refractory metals may include, consistessentially of, or consist of the same material (e.g., metal or metalalloy). Two or more (in any combination), or even each, of the first,second, third, fourth, fifth, sixth, and seventh refractory metals mayinclude, consist essentially of, or consist of different materials(e.g., metals or metal alloys). The threaded lower end of each secondsupport post may be engaged with and/or receivable within a threadedaperture in the second shelf. The apparatus may include one or moreadditional shelves disposed between the second shelf and the thirdshelf. One or more of the additional shelves may define a plurality ofperforations therethrough.

The first shelf may define a central aperture therethrough. The centralaperture may have the shape of a square, rectangle, or circle. Theapparatus may include a shelf support disposed below the first shelf.The shelf support may include or consist essentially of a plurality ofinterconnected cross braces. One or more of the cross braces mayinclude, consist essentially of, or consist of a fourth refractory metalhaving a melting point greater than the process temperature. Theapparatus may include a first support tube. The first support tube mayhave a lower end for extending through the central aperture of the firstshelf. The lower end of the first support tube may define a plurality ofnotches. One or more of the notches may be configured to receive thereinone of the cross braces of the shelf support. The first support tube mayinclude, consist essentially of, or consist of a fifth refractory metalhaving a melting point greater than the process temperature. The fourthand/or fifth refractory metals may include, consist essentially of, orconsist of a TZM alloy The TZM alloy may include, consist essentiallyof, or consist of approximately 0.40-approximately 0.55 weight percentTi, approximately 0.06-approximately 0.12 weight percent Zr, and thebalance Mo. The TZM alloy may include, consist essentially of, orconsist of approximately 0.50 weight percent Ti, approximately 0.08weight percent Zr, and the balance Mo. The fourth and/or fifthrefractory metals may include, consist essentially of, or consist of Nb,Ta, Re, W, and/or Mo. The first support tube may have an upper endopposite the lower end. The upper end of the first support tube maydefine therein a plurality of notches. The apparatus may include a firstsupport brace including or consisting essentially of a plurality ofappendages for supporting the second shelf thereon. One or more of theappendages may be configured for receipt into one of the notches of theupper end of the first support tube. The appendages of the support bracemay define a cross shape. The second shelf may define a central aperturetherethrough. The central aperture may have the shape of a square,rectangle, or circle. The apparatus may include a second support tube.The second support tube may have a lower end for extending through thecentral aperture of the second shelf. The lower end of the secondsupport tube may define a plurality of notches. One or more of thenotches may be configured to receive therein one of the appendages ofthe support brace. The second support tube may include, consistessentially of, or consist of a sixth refractory metal having a meltingpoint greater than the process temperature. The second support tube mayhave an upper end opposite the lower end. The upper end of the secondsupport tube may define therein a plurality of notches. The sixthrefractory metal may include, consist essentially of, or consist of aTZM alloy The TZM alloy may include, consist essentially of, or consistof approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The sixth refractory metal may include, consistessentially of, or consist of Nb, Ta, Re, W, and/or Mo. The apparatusmay include a base disposed beneath the shelf support. The base mayinclude or consist essentially of (i) a plurality of spaced-apart crossbars each defining a plurality of apertures therethrough, and (ii) aplurality of spaced-apart through rods each extending through theapertures of multiple ones of the cross bars. The base may include oneor more alignment features (e.g., posts, brackets, plates, etc.)extending upward therefrom. The shelf support may include one or morebrackets each for receiving one of the one or more alignment features.

The apparatus may include a base disposed beneath the first shelf. Thebase may include or consist essentially of (i) a plurality ofspaced-apart cross bars each defining a plurality of aperturestherethrough, and (ii) a plurality of spaced-apart through rods eachextending through the apertures of multiple ones of the cross bars. Oneor more of the cross bars may include, consist essentially of, orconsist of a fourth refractory metal having a melting point greater thanthe process temperature. One or more of the through rods may include,consist essentially of, or consist of a fifth refractory metal having amelting point greater than the process temperature. The fourth and/orfifth refractory metals may include, consist essentially of, or consistof a TZM alloy. The TZM alloy may include, consist essentially of, orconsist of approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The fourth and/or fifth refractory metals mayinclude, consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo.The apparatus may include a shelf support disposed below the first shelfand/or disposed above the base. The shelf support may include or consistessentially of a plurality of interconnected cross braces. One or moreof the cross braces metals may include, consist essentially of, orconsist of a sixth refractory metal having a melting point greater thanthe process temperature. The base may include one or more alignmentfeatures (e.g., posts, brackets, plates, etc.) extending upwardtherefrom. The shelf support may include one or more brackets each forreceiving one of the one or more alignment features. The sixthrefractory metal may include, consist essentially of, or consist of aTZM alloy. The TZM alloy may include, consist essentially of, or consistof approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The sixth refractory metal may include, consistessentially of, or consist of Nb, Ta, Re, W, and/or Mo.

In another aspect, embodiments of the invention feature a method ofhigh-temperature brazing at a process temperature greater thanapproximately 1000° C. An apparatus is disposed within a furnacechamber. The apparatus includes or consists essentially of a firstshelf, a plurality of first support posts, and a second shelf. The firstshelf includes, consists essentially of, or consists of a firstrefractory metal having a melting point greater than the processtemperature. The first shelf defines therein or therethrough a pluralityof apertures, each aperture being threaded through at least a portion ofits thickness. One or more of the first support posts includes, consistsessentially of, or consists of a second refractory metal having amelting point greater than the process temperature. One or more of thefirst support posts has a threaded lower end for engagement with athreaded aperture of the first shelf. One or more of the first supportposts defines a support collar proximate an upper end opposite thethreaded lower end. A lateral dimension (e.g., a width or diameter) ofthe first support post above the support collar is smaller than alateral dimension (e.g., a width or diameter) of the first support postbelow the support collar. The second shelf includes, consistsessentially of, or consists of a third refractory metal having a meltingpoint greater than the process temperature. The second shelf definestherein or therethrough a plurality of apertures. One or more aperturesof the second shelf receives and/or is configured to receive the upperend of one of the lower support posts such that a portion of the secondshelf proximate each aperture thereof rests upon the support collar ofthe first support post received in the aperture. On the first shelfand/or the second shelf of the apparatus are disposed (i) a firstcomponent, (ii) a second component, and (iii) a brazing materialdisposed between the first and second components. The brazing materialmay be in direct contact with the first and second components. Aprocessing ambient is introduced within the furnace chamber. The processtemperature is applied within the furnace chamber, thereby melting thebrazing material and joining the first and second components at a brazedjoint therebetween.

Embodiments of the invention may include one or more of the following inany of a variety of combinations. The first and/or second components mayinclude, consist essentially of, or consist of a metallic part. Theapparatus may resist creep deformation at the process temperature.Introducing the processing ambient may include or consist essentially ofat least partially evacuating the furnace chamber (i.e., introducing avacuum therein). Introducing the processing ambient may include orconsist essentially of introducing a process gas within the furnacechamber. The process gas may include, consist essentially of, or consistof hydrogen.

The first, second, and/or third refractory metals may include, consistessentially of, or consist of a TZM alloy. The TZM alloy may include,consist essentially of, or consist of approximately 0.40-approximately0.55 weight percent Ti, approximately 0.06-approximately 0.12 weightpercent Zr, and the balance Mo. The TZM alloy may include, consistessentially of, or consist of approximately 0.50 weight percent Ti,approximately 0.08 weight percent Zr, and the balance Mo. The first,second, and/or third refractory metals may include, consist essentiallyof, or consist of Nb, Ta, Re, W, and/or Mo. The first shelf and/or thesecond shelf may define a plurality of perforations therethrough. Thethreaded lower end of each of the first support posts may include asupport shoulder defined therein. The apparatus may include a thirdshelf and a plurality of second support posts. The third shelf mayinclude, consist essentially of, or consist of a fourth refractory metalhaving a melting point greater than the process temperature. The thirdshelf may define therein or therethrough a plurality of apertures. Oneor more of the second support posts may include, consist essentially of,or consist of a fifth refractory metal having a melting point greaterthan the process temperature. One or more of the second support postsmay have a threaded lower end for engagement with a threaded aperture.One or more of the second support posts may define a support collarproximate an upper end opposite the threaded lower end. A lateraldimension (e.g., a width or diameter) of the second support post abovethe support collar may be smaller than a lateral dimension (e.g., awidth or diameter) of the second support post below the support collar.One or more of the second support posts may define a dowel pin mountthrough the upper end thereof above the support collar. The upper end ofone or more of the second support posts is receivable and/or receivedwithin an aperture of the third shelf such that (i) a portion of thethird shelf proximate each aperture thereof rests upon the supportcollar of the second support post received in the aperture, and (ii) thedowel pin mount of the second support post is disposed above a topsurface of the third shelf. The fourth and/or fifth refractory metalsmay include, consist essentially of, or consist of a TZM alloy. The TZMalloy may include, consist essentially of, or consist of approximately0.40-approximately 0.55 weight percent Ti, approximately0.06-approximately 0.12 weight percent Zr, and the balance Mo. The TZMalloy may include, consist essentially of, or consist of approximately0.50 weight percent Ti, approximately 0.08 weight percent Zr, and thebalance Mo. The fourth and/or fifth refractory metals may include,consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo.

The threaded lower end of one or more of the second support posts mayinclude a support shoulder defined therein. The third shelf may define aplurality of perforations therethrough. The apparatus may include aplurality of locking pins. One or more of the locking pins may include,consist essentially of, or consist of a sixth refractory metal having amelting point greater than the process temperature. One or more of thelocking pins may be receivable and/or received within a dowel pin mountof a second support post, thereby preventing disengagement of the secondsupport posts from the third shelf. The sixth refractory metal mayinclude, consist essentially of, or consist of a TZM alloy. The TZMalloy may include, consist essentially of, or consist of approximately0.40-approximately 0.55 weight percent Ti, approximately0.06-approximately 0.12 weight percent Zr, and the balance Mo. The TZMalloy may include, consist essentially of, or consist of approximately0.50 weight percent Ti, approximately 0.08 weight percent Zr, and thebalance Mo. The sixth refractory metal may include, consist essentiallyof, or consist of Nb, Ta, Re, W, and/or Mo. One or more of the lockingpins may define one or more apertures therethrough.

The apparatus may include a plurality of retaining wires. One or more ofthe retaining wires may include, consist essentially of, or consist of aseventh refractory metal having a melting point greater than the processtemperature. One or more of the retaining wires may be receivable and/orreceived within an aperture of a locking pin, thereby preventingdisengagement of the locking pin from the second support post in whichit is received or receivable. The seventh refractory metal may include,consist essentially of, or consist of a TZM alloy. The TZM alloy mayinclude, consist essentially of, or consist of approximately0.40-approximately 0.55 weight percent Ti, approximately0.06-approximately 0.12 weight percent Zr, and the balance Mo. The TZMalloy may include, consist essentially of, or consist of approximately0.50 weight percent Ti, approximately 0.08 weight percent Zr, and thebalance Mo. The seventh refractory metal may include, consistessentially of, or consist of Nb, Ta, Re, W, and/or Mo. Two or more (inany combination), or even all, of the first, second, third, fourth,fifth, sixth, and seventh refractory metals may include, consistessentially of, or consist of the same material (e.g., metal or metalalloy). Two or more (in any combination), or even each, of the first,second, third, fourth, fifth, sixth, and seventh refractory metals mayinclude, consist essentially of, or consist of different materials(e.g., metals or metal alloys). The threaded lower end of each secondsupport post may be engaged with and/or receivable within a threadedaperture in the second shelf. The apparatus may include one or moreadditional shelves disposed between the second shelf and the thirdshelf. One or more of the additional shelves may define a plurality ofperforations therethrough.

The first shelf may define a central aperture therethrough. The centralaperture may have the shape of a square, rectangle, or circle. Theapparatus may include a shelf support disposed below the first shelf.The shelf support may include or consist essentially of a plurality ofinterconnected cross braces. One or more of the cross braces mayinclude, consist essentially of, or consist of a fourth refractory metalhaving a melting point greater than the process temperature. Theapparatus may include a first support tube. The first support tube mayhave a lower end for extending through the central aperture of the firstshelf. The lower end of the first support tube may define a plurality ofnotches. One or more of the notches may be configured to receive thereinone of the cross braces of the shelf support. The first support tube mayinclude, consist essentially of, or consist of a fifth refractory metalhaving a melting point greater than the process temperature. The fourthand/or fifth refractory metals may include, consist essentially of, orconsist of a TZM alloy. The TZM alloy may include, consist essentiallyof, or consist of approximately 0.40-approximately 0.55 weight percentTi, approximately 0.06-approximately 0.12 weight percent Zr, and thebalance Mo. The TZM alloy may include, consist essentially of, orconsist of approximately 0.50 weight percent Ti, approximately 0.08weight percent Zr, and the balance Mo. The fourth and/or fifthrefractory metals may include, consist essentially of, or consist of Nb,Ta, Re, W, and/or Mo. The first support tube may have an upper endopposite the lower end. The upper end of the first support tube maydefine therein a plurality of notches. The apparatus may include a firstsupport brace including or consisting essentially of a plurality ofappendages for supporting the second shelf thereon. One or more of theappendages may be configured for receipt into one of the notches of theupper end of the first support tube. The appendages of the support bracemay define a cross shape. The second shelf may define a central aperturetherethrough. The central aperture may have the shape of a square,rectangle, or circle. The apparatus may include a second support tube.The second support tube may have a lower end for extending through thecentral aperture of the second shelf. The lower end of the secondsupport tube may define a plurality of notches. One or more of thenotches may be configured to receive therein one of the appendages ofthe support brace. The second support tube may include, consistessentially of, or consist of a sixth refractory metal having a meltingpoint greater than the process temperature. The second support tube mayhave an upper end opposite the lower end. The upper end of the secondsupport tube may define therein a plurality of notches. The sixthrefractory metal may include, consist essentially of, or consist of aTZM alloy. The TZM alloy may include, consist essentially of, or consistof approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The sixth refractory metal may include, consistessentially of, or consist of Nb, Ta, Re, W, and/or Mo. The apparatusmay include a base disposed beneath the shelf support. The base mayinclude or consist essentially of (i) a plurality of spaced-apart crossbars each defining a plurality of apertures therethrough, and (ii) aplurality of spaced-apart through rods each extending through theapertures of multiple ones of the cross bars. The base may include oneor more alignment features (e.g., posts, brackets, plates, etc.)extending upward therefrom. The shelf support may include one or morebrackets each for receiving one of the one or more alignment features.

The apparatus may include a base disposed beneath the first shelf. Thebase may include or consist essentially of (i) a plurality ofspaced-apart cross bars each defining a plurality of aperturestherethrough, and (ii) a plurality of spaced-apart through rods eachextending through the apertures of multiple ones of the cross bars. Oneor more of the cross bars may include, consist essentially of, orconsist of a fourth refractory metal having a melting point greater thanthe process temperature. One or more of the through rods may include,consist essentially of, or consist of a fifth refractory metal having amelting point greater than the process temperature. The fourth and/orfifth refractory metals may include, consist essentially of, or consistof a TZM alloy. The TZM alloy may include, consist essentially of, orconsist of approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The fourth and/or fifth refractory metals mayinclude, consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo.The apparatus may include a shelf support disposed below the first shelfand/or disposed above the base. The shelf support may include or consistessentially of a plurality of interconnected cross braces. One or moreof the cross braces metals may include, consist essentially of, orconsist of a sixth refractory metal having a melting point greater thanthe process temperature. The base may include one or more alignmentfeatures (e.g., posts, brackets, plates, etc.) extending upwardtherefrom. The shelf support may include one or more brackets each forreceiving one of the one or more alignment features. The sixthrefractory metal may include, consist essentially of, or consist of aTZM alloy. The TZM alloy may include, consist essentially of, or consistof approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The sixth refractory metal may include, consistessentially of, or consist of Nb, Ta, Re, W, and/or Mo.

In yet another aspect, embodiments of the invention feature an apparatusfor receiving and supporting one or more components during processingthereof at a process temperature greater than approximately 1000° C. Theapparatus includes or consists essentially of a first shelf, a secondshelf disposed over the first shelf, a plurality of first support posts,and a plurality of first nuts. The first shelf includes, consistsessentially of, or consists of a first refractory metal having a meltingpoint greater than the process temperature. The first shelf definestherein or therethrough a plurality of apertures. The second shelfincludes, consists essentially of, or consists of a second refractorymetal having a melting point greater than the process temperature. Thesecond shelf defines therein or therethrough a plurality of apertures.The second shelf includes one or more first lift hooks extendingtherefrom. The one or more first lift hooks may extend from a topsurface and/or a perimeter of the second shelf. The first shelf mayinclude one or more lift hooks extending therefrom. One or more of thefirst support posts includes, consists essentially of, or consists of athird refractory metal having a melting point greater than the processtemperature. One or more of the first support posts has a tapered lowerend for engagement with an aperture of the first shelf. One or more ofthe first support posts has a threaded upper end opposite the lower end.One or more of the first support posts defines a support collarproximate the upper end. A lateral dimension (e.g., a width or diameter)of the first support post above the support collar is smaller than alateral dimension (e.g., a width or diameter) of the first support postbelow the support collar. When an upper end of a first support post isreceived in an aperture of the second shelf, a portion of the secondshelf proximate the aperture rests upon the support collar of the firstsupport post received in the aperture. When an upper end of a firstsupport post is received in an aperture of the second shelf, at least aportion of the upper end of the first support post may extend above atop surface of the second shelf. One or more of the first nuts includes,consists essentially of, or consists of a fourth refractory metal havinga melting point greater than the process temperature. One or more of thefirst nuts defines therein a lower aperture. At least a portion of thelower aperture may be threaded for engagement with an upper end of afirst support post. One or more of the first nuts defines therein anupper aperture. At least a portion of the upper aperture may be tapered.The lower aperture and the upper aperture of at least one of the firstnuts may be connected to form an aperture extending through an entirethickness thereof. The lower aperture and the upper aperture of at leastone of the first nuts may be isolated from each other (i.e., separatedfrom each other by a portion of the first nut therebetween). The secondshelf, the first support posts, and the first nuts may be collectivelyseparable, as a modular unit, from the first shelf via a lifting forceapplied via the one or more first lift hooks.

Embodiments of the invention may include one or more of the following inany of a variety of combinations. One or more of the components may be ametallic part. The apparatus may resist creep deformation at the processtemperature. The first, second, third, and/or fourth refractory metalsmay include, consist essentially of, or consist of a TZM alloy. The TZMalloy may include, consist essentially of, or consist of approximately0.40-approximately 0.55 weight percent Ti, approximately0.06-approximately 0.12 weight percent Zr, and the balance Mo. The TZMalloy may include, consist essentially of, or consist of approximately0.50 weight percent Ti, approximately 0.08 weight percent Zr, and thebalance Mo. The first, second, third, and/or fourth refractory metalsmay include, consist essentially of, or consist of Nb, Ta, Re, W, and/orMo. The first shelf and/or the second shelf may define a plurality ofperforations therethrough.

The apparatus may include a third shelf disposed over the second shelf,a plurality of second support posts, and a plurality of second nuts. Thethird shelf may include, consist essentially of, or consist of a fifthrefractory metal having a melting point greater than the processtemperature. The third shelf may define therethrough a plurality ofapertures. The third shelf may include one or more second lift hooksextending therefrom. The one or more second lift hooks may extend from atop surface and/or a perimeter of the third shelf. The third shelf maydefine a plurality of perforations therethrough. One or more of thesecond support posts may include, consist essentially of, or consist ofa sixth refractory metal having a melting point greater than the processtemperature. One or more of the second support posts may have a taperedlower end for engagement with an upper aperture of a first nut. One ormore of the second support posts may have a threaded upper end oppositethe tapered lower end. One or more of the second support posts maydefine a support collar proximate the upper end. A lateral dimension(e.g., a width or diameter) of the second support post above the supportcollar being smaller than a lateral dimension (e.g., a width ordiameter) of the second support post below the support collar. When anupper end of a second support post is received in an aperture of thethird shelf, a portion of the third shelf proximate the aperture mayrest upon the support collar of the second support post received in theaperture. When an upper end of a second support post is received in anaperture of the third shelf, at least a portion of the upper end of thesecond support post may extend above a top surface of the third shelf.One or more of the second nuts may include, consist essentially of, orconsist of a seventh refractory metal having a melting point greaterthan the process temperature. One or more of the second nuts may definetherein a lower aperture. At least a portion of the lower aperture maybe threaded for engagement with an upper end of a second support post.The third shelf, the second support posts, and the second nuts may becollectively separable, as a modular unit, from the second shelf and thefirst shelf via a lifting force applied via the one or more second lifthooks. One or more of the second nuts may define therein an upperaperture. At least a portion of the upper aperture may be tapered. Thelower aperture and the upper aperture of at least one of the second nutsmay be connected to form an aperture extending through an entirethickness thereof. The lower aperture and the upper aperture of at leastone of the second nuts may be isolated from each other (i.e., separatedfrom each other by a portion of the second nut therebetween). The fifth,sixth, and/or seventh refractory metals may include, consist essentiallyof, or consist of a TZM alloy. The TZM alloy may include, consistessentially of, or consist of approximately 0.40-approximately 0.55weight percent Ti, approximately 0.06-approximately 0.12 weight percentZr, and the balance Mo. The TZM alloy may include, consist essentiallyof, or consist of approximately 0.50 weight percent Ti, approximately0.08 weight percent Zr, and the balance Mo. The fifth, sixth, and/orseventh refractory metals may include, consist essentially of, orconsist of Nb, Ta, Re, W, and/or Mo. Two or more (in any combination),or even all, of the first, second, third, fourth, fifth, sixth, andseventh refractory metals may include, consist essentially of, orconsist of the same material (e.g., metal or metal alloy). Two or more(in any combination), or even each, of the first, second, third, fourth,fifth, sixth, and seventh refractory metals may include, consistessentially of, or consist of different materials (e.g., metals or metalalloys).

The first shelf may define a central aperture therethrough. The centralaperture may have the shape of a square, rectangle, or circle. Theapparatus may include a shelf support disposed below the first shelf.The shelf support may include or consist essentially of a plurality ofinterconnected cross braces. One or more of the cross braces mayinclude, consist essentially of, or consist of a fifth refractory metalhaving a melting point greater than the process temperature. Theapparatus may include a first support tube. The first support tube mayhave a lower end for extending through the central aperture of the firstshelf. The lower end of the first support tube may define a plurality ofnotches. One or more of the notches may be configured to receive thereinone of the cross braces of the shelf support. The first support tube mayinclude, consist essentially of, or consist of a sixth refractory metalhaving a melting point greater than the process temperature. The fifthand/or sixth refractory metals may include, consist essentially of, orconsist of a TZM alloy. The TZM alloy may include, consist essentiallyof, or consist of approximately 0.40-approximately 0.55 weight percentTi, approximately 0.06-approximately 0.12 weight percent Zr, and thebalance Mo. The TZM alloy may include, consist essentially of, orconsist of approximately 0.50 weight percent Ti, approximately 0.08weight percent Zr, and the balance Mo. The fifth and/or sixth refractorymetals may include, consist essentially of, or consist of Nb, Ta, Re, W,and/or Mo. The first support tube may have an upper end opposite thelower end. The upper end of the first support tube may define therein aplurality of notches. The apparatus may include a first support braceincluding or consisting essentially of a plurality of appendages forsupporting the second shelf thereon. One or more of the appendages maybe configured for receipt into one of the notches of the upper end ofthe first support tube. The appendages of the support brace may define across shape. The second shelf may define a central aperturetherethrough. The central aperture may have the shape of a square,rectangle, or circle. The apparatus may include a second support tube.The second support tube may have a lower end for extending through thecentral aperture of the second shelf. The lower end of the secondsupport tube may define a plurality of notches. One or more of thenotches may be configured to receive therein one of the appendages ofthe support brace. The second support tube may include, consistessentially of, or consist of a seventh refractory metal having amelting point greater than the process temperature. The second supporttube may have an upper end opposite the lower end. The upper end of thesecond support tube may define therein a plurality of notches. Theseventh refractory metal may include, consist essentially of, or consistof a TZM alloy. The TZM alloy may include, consist essentially of, orconsist of approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The seventh refractory metal may include,consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo. Two ormore (in any combination), or even all, of the first, second, third,fourth, fifth, sixth, and seventh refractory metals may include, consistessentially of, or consist of the same material (e.g., metal or metalalloy). Two or more (in any combination), or even each, of the first,second, third, fourth, fifth, sixth, and seventh refractory metals mayinclude, consist essentially of, or consist of different materials(e.g., metals or metal alloys). The apparatus may include a basedisposed beneath the shelf support. The base may include or consistessentially of (i) a plurality of spaced-apart cross bars each defininga plurality of apertures therethrough, and (ii) a plurality ofspaced-apart through rods each extending through the apertures ofmultiple ones of the cross bars. The base may include one or morealignment features (e.g., posts, brackets, plates, etc.) extendingupward therefrom. The shelf support may include one or more bracketseach for receiving one of the one or more alignment features.

The apparatus may include a base disposed beneath the first shelf. Thebase may include or consist essentially of (i) a plurality ofspaced-apart cross bars each defining a plurality of aperturestherethrough, and (ii) a plurality of spaced-apart through rods eachextending through the apertures of multiple ones of the cross bars. Oneor more of the cross bars may include, consist essentially of, orconsist of a fifth refractory metal having a melting point greater thanthe process temperature. One or more of the through rods may include,consist essentially of, or consist of a sixth refractory metal having amelting point greater than the process temperature. The fifth and/orsixth refractory metals may include, consist essentially of, or consistof a TZM alloy. The TZM alloy may include, consist essentially of, orconsist of approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The fifth and/or sixth refractory metals mayinclude, consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo.The apparatus may include a shelf support disposed below the first shelfand/or disposed above the base. The shelf support may include or consistessentially of a plurality of interconnected cross braces. One or moreof the cross braces metals may include, consist essentially of, orconsist of a seventh refractory metal having a melting point greaterthan the process temperature. The base may include one or more alignmentfeatures (e.g., posts, brackets, plates, etc.) extending upwardtherefrom. The shelf support may include one or more brackets each forreceiving one of the one or more alignment features. The seventhrefractory metal may include, consist essentially of, or consist of aTZM alloy. The TZM alloy may include, consist essentially of, or consistof approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The seventh refractory metal may include,consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo. Two ormore (in any combination), or even all, of the first, second, third,fourth, fifth, sixth, and seventh refractory metals may include, consistessentially of, or consist of the same material (e.g., metal or metalalloy). Two or more (in any combination), or even each, of the first,second, third, fourth, fifth, sixth, and seventh refractory metals mayinclude, consist essentially of, or consist of different materials(e.g., metals or metal alloys).

In another aspect, embodiments of the invention feature a method ofhigh-temperature brazing at a process temperature greater thanapproximately 1000° C. An apparatus is disposed within a furnacechamber. The apparatus includes or consists essentially of a firstshelf, a second shelf disposed over the first shelf, a plurality offirst support posts, and a plurality of first nuts. The first shelfincludes, consists essentially of, or consists of a first refractorymetal having a melting point greater than the process temperature. Thefirst shelf defines therein or therethrough a plurality of apertures.The second shelf includes, consists essentially of, or consists of asecond refractory metal having a melting point greater than the processtemperature. The second shelf defines therein or therethrough aplurality of apertures. The second shelf includes one or more first lifthooks extending therefrom. The one or more first lift hooks may extendfrom a top surface and/or a perimeter of the second shelf. The firstshelf may include one or more lift hooks extending therefrom. One ormore of the first support posts includes, consists essentially of, orconsists of a third refractory metal having a melting point greater thanthe process temperature. One or more of the first support posts has atapered lower end for engagement with an aperture of the first shelf.One or more of the first support posts has a threaded upper end oppositethe lower end. One or more of the first support posts defines a supportcollar proximate the upper end. A lateral dimension (e.g., a width ordiameter) of the first support post above the support collar is smallerthan a lateral dimension (e.g., a width or diameter) of the firstsupport post below the support collar. When an upper end of a firstsupport post is received in an aperture of the second shelf, a portionof the second shelf proximate the aperture rests upon the support collarof the first support post received in the aperture. When an upper end ofa first support post is received in an aperture of the second shelf, atleast a portion of the upper end of the first support post may extendabove a top surface of the second shelf. One or more of the first nutsincludes, consists essentially of, or consists of a fourth refractorymetal having a melting point greater than the process temperature. Oneor more of the first nuts defines therein a lower aperture. At least aportion of the lower aperture may be threaded for engagement with anupper end of a first support post. One or more of the first nuts definestherein an upper aperture. At least a portion of the upper aperture maybe tapered. The lower aperture and the upper aperture of at least one ofthe first nuts may be connected to form an aperture extending through anentire thickness thereof. The lower aperture and the upper aperture ofat least one of the first nuts may be isolated from each other (i.e.,separated from each other by a portion of the first nut therebetween).The second shelf, the first support posts, and the first nuts may becollectively separable, as a modular unit, from the first shelf via alifting force applied via the one or more first lift hooks. On the firstshelf and/or the second shelf of the apparatus are disposed (i) a firstcomponent, (ii) a second component, and (iii) a brazing materialdisposed between the first and second components. The brazing materialmay be in direct contact with the first and second components. Aprocessing ambient is introduced within the furnace chamber. The processtemperature is applied within the furnace chamber, thereby melting thebrazing material and joining the first and second components at a brazedjoint therebetween.

Embodiments of the invention may include one or more of the following inany of a variety of combinations. The first and/or second components mayinclude, consist essentially of, or consist of a metallic part. Theapparatus may resist creep deformation at the process temperature.Introducing the processing ambient may include or consist essentially ofat least partially evacuating the furnace chamber (i.e., introducing avacuum therein). Introducing the processing ambient may include orconsist essentially of introducing a process gas within the furnacechamber. The process gas may include, consist essentially of, or consistof hydrogen.

The first, second, third, and/or fourth refractory metals may include,consist essentially of, or consist of a TZM alloy. The TZM alloy mayinclude, consist essentially of, or consist of approximately0.40-approximately 0.55 weight percent Ti, approximately0.06-approximately 0.12 weight percent Zr, and the balance Mo. The TZMalloy may include, consist essentially of, or consist of approximately0.50 weight percent Ti, approximately 0.08 weight percent Zr, and thebalance Mo. The first, second, third, and/or fourth refractory metalsmay include, consist essentially of, or consist of Nb, Ta, Re, W, and/orMo. The first shelf and/or the second shelf may define a plurality ofperforations therethrough.

The apparatus may include a third shelf disposed over the second shelf,a plurality of second support posts, and a plurality of second nuts. Thethird shelf may include, consist essentially of, or consist of a fifthrefractory metal having a melting point greater than the processtemperature. The third shelf may define therethrough a plurality ofapertures. The third shelf may include one or more second lift hooksextending therefrom. The one or more second lift hooks may extend from atop surface and/or a perimeter of the third shelf. The third shelf maydefine a plurality of perforations therethrough. One or more of thesecond support posts may include, consist essentially of, or consist ofa sixth refractory metal having a melting point greater than the processtemperature. One or more of the second support posts may have a taperedlower end for engagement with an upper aperture of a first nut. One ormore of the second support posts may have a threaded upper end oppositethe tapered lower end. One or more of the second support posts maydefine a support collar proximate the upper end. A lateral dimension(e.g., a width or diameter) of the second support post above the supportcollar being smaller than a lateral dimension (e.g., a width ordiameter) of the second support post below the support collar. When anupper end of a second support post is received in an aperture of thethird shelf, a portion of the third shelf proximate the aperture mayrest upon the support collar of the second support post received in theaperture. When an upper end of a second support post is received in anaperture of the third shelf, at least a portion of the upper end of thesecond support post may extend above a top surface of the third shelf.One or more of the second nuts may include, consist essentially of, orconsist of a seventh refractory metal having a melting point greaterthan the process temperature. One or more of the second nuts may definetherein a lower aperture. At least a portion of the lower aperture maybe threaded for engagement with an upper end of a second support post.The third shelf, the second support posts, and the second nuts may becollectively separable, as a modular unit, from the second shelf and thefirst shelf via a lifting force applied via the one or more second lifthooks. One or more of the second nuts may define therein an upperaperture. At least a portion of the upper aperture may be tapered. Thelower aperture and the upper aperture of at least one of the second nutsmay be connected to form an aperture extending through an entirethickness thereof. The lower aperture and the upper aperture of at leastone of the second nuts may be isolated from each other (i.e., separatedfrom each other by a portion of the second nut therebetween). The fifth,sixth, and/or seventh refractory metals may include, consist essentiallyof, or consist of a TZM alloy. The TZM alloy may include, consistessentially of, or consist of approximately 0.40-approximately 0.55weight percent Ti, approximately 0.06-approximately 0.12 weight percentZr, and the balance Mo. The TZM alloy may include, consist essentiallyof, or consist of approximately 0.50 weight percent Ti, approximately0.08 weight percent Zr, and the balance Mo. The fifth, sixth, and/orseventh refractory metals may include, consist essentially of, orconsist of Nb, Ta, Re, W, and/or Mo. Two or more (in any combination),or even all, of the first, second, third, fourth, fifth, sixth, andseventh refractory metals may include, consist essentially of, orconsist of the same material (e.g., metal or metal alloy). Two or more(in any combination), or even each, of the first, second, third, fourth,fifth, sixth, and seventh refractory metals may include, consistessentially of, or consist of different materials (e.g., metals or metalalloys).

The first shelf may define a central aperture therethrough. The centralaperture may have the shape of a square, rectangle, or circle. Theapparatus may include a shelf support disposed below the first shelf.The shelf support may include or consist essentially of a plurality ofinterconnected cross braces. One or more of the cross braces mayinclude, consist essentially of, or consist of a fifth refractory metalhaving a melting point greater than the process temperature. Theapparatus may include a first support tube. The first support tube mayhave a lower end for extending through the central aperture of the firstshelf. The lower end of the first support tube may define a plurality ofnotches. One or more of the notches may be configured to receive thereinone of the cross braces of the shelf support. The first support tube mayinclude, consist essentially of, or consist of a sixth refractory metalhaving a melting point greater than the process temperature. The fifthand/or sixth refractory metals may include, consist essentially of, orconsist of a TZM alloy. The TZM alloy may include, consist essentiallyof, or consist of approximately 0.40-approximately 0.55 weight percentTi, approximately 0.06-approximately 0.12 weight percent Zr, and thebalance Mo. The TZM alloy may include, consist essentially of, orconsist of approximately 0.50 weight percent Ti, approximately 0.08weight percent Zr, and the balance Mo. The fifth and/or sixth refractorymetals may include, consist essentially of, or consist of Nb, Ta, Re, W,and/or Mo. The first support tube may have an upper end opposite thelower end. The upper end of the first support tube may define therein aplurality of notches. The apparatus may include a first support braceincluding or consisting essentially of a plurality of appendages forsupporting the second shelf thereon. One or more of the appendages maybe configured for receipt into one of the notches of the upper end ofthe first support tube. The appendages of the support brace may define across shape. The second shelf may define a central aperturetherethrough. The central aperture may have the shape of a square,rectangle, or circle. The apparatus may include a second support tube.The second support tube may have a lower end for extending through thecentral aperture of the second shelf. The lower end of the secondsupport tube may define a plurality of notches. One or more of thenotches may be configured to receive therein one of the appendages ofthe support brace. The second support tube may include, consistessentially of, or consist of a seventh refractory metal having amelting point greater than the process temperature. The second supporttube may have an upper end opposite the lower end. The upper end of thesecond support tube may define therein a plurality of notches. Theseventh refractory metal may include, consist essentially of, or consistof a TZM alloy. The TZM alloy may include, consist essentially of, orconsist of approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The seventh refractory metal may include,consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo. Two ormore (in any combination), or even all, of the first, second, third,fourth, fifth, sixth, and seventh refractory metals may include, consistessentially of, or consist of the same material (e.g., metal or metalalloy). Two or more (in any combination), or even each, of the first,second, third, fourth, fifth, sixth, and seventh refractory metals mayinclude, consist essentially of, or consist of different materials(e.g., metals or metal alloys). The apparatus may include a basedisposed beneath the shelf support. The base may include or consistessentially of (i) a plurality of spaced-apart cross bars each defininga plurality of apertures therethrough, and (ii) a plurality ofspaced-apart through rods each extending through the apertures ofmultiple ones of the cross bars. The base may include one or morealignment features (e.g., posts, brackets, plates, etc.) extendingupward therefrom. The shelf support may include one or more bracketseach for receiving one of the one or more alignment features.

The apparatus may include abase disposed beneath the first shelf. Thebase may include or consist essentially of (i) a plurality ofspaced-apart cross bars each defining a plurality of aperturestherethrough, and (ii) a plurality of spaced-apart through rods eachextending through the apertures of multiple ones of the cross bars. Oneor more of the cross bars may include, consist essentially of, orconsist of a fifth refractory metal having a melting point greater thanthe process temperature. One or more of the through rods may include,consist essentially of, or consist of a sixth refractory metal having amelting point greater than the process temperature. The fifth and/orsixth refractory metals may include, consist essentially of, or consistof a TZM alloy. The TZM alloy may include, consist essentially of, orconsist of approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The fifth and/or sixth refractory metals mayinclude, consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo.The apparatus may include a shelf support disposed below the first shelfand/or disposed above the base. The shelf support may include or consistessentially of a plurality of interconnected cross braces. One or moreof the cross braces metals may include, consist essentially of, orconsist of a seventh refractory metal having a melting point greaterthan the process temperature. The base may include one or more alignmentfeatures (e.g., posts, brackets, plates, etc.) extending upwardtherefrom. The shelf support may include one or more brackets each forreceiving one of the one or more alignment features. The seventhrefractory metal may include, consist essentially of, or consist of aTZM alloy. The TZM alloy may include, consist essentially of, or consistof approximately 0.40-approximately 0.55 weight percent Ti,approximately 0.06-approximately 0.12 weight percent Zr, and the balanceMo. The TZM alloy may include, consist essentially of, or consist ofapproximately 0.50 weight percent Ti, approximately 0.08 weight percentZr, and the balance Mo. The seventh refractory metal may include,consist essentially of, or consist of Nb, Ta, Re, W, and/or Mo. Two ormore (in any combination), or even all, of the first, second, third,fourth, fifth, sixth, and seventh refractory metals may include, consistessentially of, or consist of the same material (e.g., metal or metalalloy). Two or more (in any combination), or even each, of the first,second, third, fourth, fifth, sixth, and seventh refractory metals mayinclude, consist essentially of, or consist of different materials(e.g., metals or metal alloys).

These and other objects, along with advantages and features of thepresent invention herein disclosed, will become more apparent throughreference to the following description, the accompanying drawings, andthe claims. Furthermore, it is to be understood that the features of thevarious embodiments described herein are not mutually exclusive and mayexist in various combinations and permutations. As used herein, theterms “approximately” and “substantially” mean±10%, and in someembodiments, ±5%. The term “consists essentially of” means excludingother materials that contribute to function, unless otherwise definedherein. Nonetheless, such other materials may be present, collectivelyor individually, in trace amounts. For example, a structure consistingessentially of multiple metals will generally include only those metalsand only unintentional impurities (which may be metallic ornon-metallic) that may be detectable via chemical analysis but do notcontribute to function. As used herein, “consisting essentially of atleast one metal” refers to a metal or a mixture of two or more metalsbut not compounds between a metal and a non-metallic element or chemicalspecies such as oxygen, silicon, or nitrogen (e.g., metal nitrides,metal silicides, or metal oxides); such non-metallic elements orchemical species may be present, collectively or individually, in traceamounts, e.g., as impurities. Herein, in a part “defining an aperturetherethrough,” the aperture extends through the thickness of the partunless otherwise indicated; in a part “defining an aperture therein,”the aperture may extend through only a portion of the thickness of thepart, or the aperture may extend through the entire thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various embodiments of the present invention are describedwith reference to the following drawings, in which:

FIGS. 1A and 1B are side views of a rack in accordance with variousembodiments of the invention;

FIG. 2A is a cross-sectional view of a threaded connection between asupport post and a shelf in accordance with various embodiments of theinvention;

FIG. 2B is a side view of a connection between a support post and ashelf utilizing a locking pin in accordance with various embodiments ofthe invention;

FIGS. 3A and 3B are side views of a locking pin in accordance withvarious embodiments of the invention;

FIG. 4 is a plan view of a retaining wire in accordance with variousembodiments of the invention;

FIG. 5 is a side view of a support post in accordance with variousembodiments of the invention;

FIG. 6 is a side view of a support post in accordance with variousembodiments of the invention;

FIG. 7 is an exploded perspective view of a rack in accordance withvarious embodiments of the invention;

FIG. 8 is a perspective view of an assembled rack in accordance withvarious embodiments of the invention;

FIG. 9 is a perspective view of an assembled rack in accordance withvarious embodiments of the invention;

FIG. 10 is a bottom view of the rack of FIG. 9;

FIG. 11A is a plan view of a rack base in accordance with variousembodiments of the invention;

FIG. 11B is a side view of the rack base of FIG. 11A;

FIG. 12A is a plan view of a shelf support in accordance with variousembodiments of the invention;

FIGS. 12B and 12C are enlarged views of portions of the shelf supportfor FIG. 12A;

FIG. 13A is a perspective view of an assembled rack in accordance withvarious embodiments of the invention;

FIG. 13B is an exploded perspective view of the rack of FIG. 13A;

FIG. 13C is a side view of a shelf-support rod module of a rack inaccordance with various embodiments of the invention;

FIG. 13D is a cross-sectional view of the module of FIG. 13C;

FIGS. 13E and 13F are enlarged views of portions of the module of FIG.13D;

FIG. 13G is a side view of a support tube in accordance with variousembodiments of the invention;

FIG. 13H is a top view of the support tube of FIG. 13G;

FIG. 13I is a side view of a support tube in accordance with variousembodiments of the invention;

FIG. 13J is a top view of the support tube of FIG. 13I;

FIG. 13K is a plan view of a support bracket in accordance with variousembodiments of the invention; and

FIG. 14 is a flowchart of an exemplary process in accordance withvarious embodiments of the invention.

DETAILED DESCRIPTION

FIGS. 1A and 1B depict side views of a support rack 100 in accordancewith embodiments of the present invention along perpendiculardirections. As shown, the rack 100 typically includes or consistsessentially of two, three, or more shelves (or “trays”) 105, 110separated by multiple lower support posts 115 and multiple upper supportposts 120. The bottom shelf 110 and upper shelves 105 are separated by aspacing h, and the rack 100 has a total height H, a width W, and a depthD. The values of h, H, W, and D may be selected to meet the needs of thespecific high-temperature process and, e.g., the size of the parts to beplaced on the shelves 105, 110 for processing and/or the size of thefurnace chamber in which the rack 100 is to be placed for processing. Invarious embodiments, as detailed below and in other figures, racks maydefine substantially cylindrical shapes and feature substantiallycircular shelves. In various embodiments, at least some of the shelves105, 110 and/or the posts 115, 120 include, consist essentially of, orconsist of one or more refractory materials (e.g., refractory metals)having melting points higher than the temperatures utilized forhigh-temperature brazing processes (e.g., 1000° C.-1100° C.). In variousembodiments, at least some of the shelves 105, 110 and/or the posts 115,120 include, consist essentially of, or consist of one or more TZMalloys. In other embodiments, at least some of the shelves 105, 110and/or the posts 115, 120 include, consist essentially of, or consist ofone or more refractory metals, e.g., Nb, Ta, Re, W, and/or Mo. Invarious embodiments, at least some of the shelves 105, 110 and/or theposts 115, 120 incorporate one or more alloying elements, for exampleLa, at concentrations of, e.g., approximately 0.01% to approximately 1%.

FIG. 2A is a magnified view of threaded bottom end 200 of a post 115engaged with a complementarily threaded hole in shelf 110, therebyforming a threaded connection between shelf 110 and support post 115,indicated as circled area A in FIG. 1A, that locks the two partstogether. In various embodiments, the threaded connection providessuperior strength and high-temperature stability (against, e.g.,deformation processes such as creep) compared with conventional pin- orrivet-based connections. In various embodiments, there is also ashoulder machined into the threaded bottom end 200 to properly align thesupport post 115 and prevent the threads from bearing the weight of theother shelves and workpieces (i.e., the load supported by the shelves).As shown, the shoulder corresponds to a portion of the post 115proximate the threaded end 200 having a larger diameter (or otherlateral dimension, for posts having non-circular cross-sections) thanthat of the threaded end 200 and/or the complementarily threaded hole towhich threaded end 200 engages.

FIG. 2B is a magnified view of the locking connection between thetopmost shelf 105 and the upper support post 120 indicated as circledarea B in FIG. 1B. As shown, the upper end 210 of the support post 120is disposed through an aperture defined by the shelf 105, and a lockingpin 215 slides through an aperture (or “dowel pin mount”) defined by thesupport post 120, thereby preventing withdrawal of the support post 120through the shelf 105. In various embodiments, the locking pin 215 isheld in place by one or more (e.g., two) retaining wires 220. In variousembodiments, the locking pin 215 and retaining wires 220 include,consist essentially of, or consist of one or more refractory materials(e.g., refractory metals) having melting points higher than thetemperatures utilized for high-temperature brazing processes (e.g.,1000° C.-1100° C.). In various embodiments, the locking pin 215 andretaining wires 220 include, consist essentially of, or consist of oneor more TZM alloys, or of one or more refractory metals, e.g., Nb, Ta,Re, W, and/or Mo. In various embodiments, the retaining wires 220include, consist essentially of, or consist of Mo. As shown in FIG. 2B,the support post 120 may also incorporate a shoulder 225 that helpssupport the weight of shelf 105 (and any workpieces thereon) whileenabling upper end 210 to fit through the aperture defined in shelf 105.

FIGS. 3A and 3B are side views of a locking pin 215 in accordance withvarious embodiments of the invention. As shown, the locking pin 215 maydefine two or more apertures 300 therethrough, each of which may receivea retaining wire 220. The locking pin 215 may also feature tapered ends305 to facilitate insertion of the locking pin 215 into the dowel pinmount of the support post 120. In various embodiments, as shown in FIG.3A, the locking pin 215 features two apertures 300 spaced apart by adistance 310 that is greater than or approximately equal to the diameter(or other lateral dimension) of upper end 210 of support post 120. Eachaperture 310 may be spaced away from an end of locking pin 215 by adistance 315 that may be, for example, approximately 20% toapproximately 50% of distance 310.

FIG. 4 is a plan view of a retaining wire 220 in accordance with variousembodiments of the invention. As shown, the retaining wire 220 may beinitially substantially straight for insertion through an aperture 300and may subsequently be deformed to incorporate one or bends to lock itinto place after insertion through an aperture 300 of a locking pin 215.The retaining wire 220 may have a substantially straight length w1between such bends, where length w1 is preferably greater than orsubstantially equal to the diameter (or other lateral dimension) of thelocking pin 215.

FIG. 5 is a side view of a lower support post 115 in accordance withvarious embodiments of the present invention. As shown, the support post115 has a threaded lower end 200 for engagement within a complementarilythreaded aperture in a shelf 110, thereby locking support post 115 andshelf 110 together. There is also a shoulder 205 machined into the lowerend 200 to support weight. As also shown, the upper end of support post115 may have a smaller diameter (or other lateral dimension) than thatof the majority of the length of support post 115, thereby forming asupport collar 500 upon which a shelf 110 rests when connected to thesupport post 115. This support collar 500 may provide additionalstability and resistance to deformation when the rack 100 is subjectedto high process temperatures. As shown, the upper end of support post115 that defines collar 500 may have a height 505 (which may be, e.g.,less than or approximately equal to the thickness of a shelf 105), andthreaded end 200 may have a height 510 (which may be, e.g., less than orapproximately equal to the thickness of a shelf 105). The center portionof the support post 115 between those ends may have a height 515 thatsubstantially defines the spacing between various shelves 105 withinrack 100.

FIG. 6 is a side view of an upper support post 120 in accordance withvarious embodiments of the present invention. As shown, the support post120 has a threaded lower end 600 for engagement within a threadedaperture in a shelf 110, thereby locking support post 120 and shelf 110together. There is also a shoulder 605 machined into the lower end tosupport weight. As also shown, the upper end 210 of support post 120 maydefine therethrough a dowel pin mount 610 for receiving a locking pin215 in order to lock support post 120 to a shelf 105, as describedabove. The upper end 210 may also feature a shoulder 615 machinedtherein to support at least some of the weight of shelf 105. As shown,the upper end 210 of support post 120 that defines collar 615 may have aheight 620 (which may be, e.g., greater than or approximately equal tothe sum of the thickness of a shelf 105 and the thickness of locking pin215), and threaded end 600 may have a height 625 (which may be, e.g.,less than or approximately equal to the thickness of a shelf 105). Thecenter portion of the support post 120 between those ends may have aheight 630 that substantially defines the spacing between a topmostshelf 105 and the shelf 105 immediately therebelow within rack 100.

FIGS. 7 and 8 are, respectively, an exploded perspective view and aperspective view of an assembled rack 100 in accordance with embodimentsof the present invention. As shown, multiple support posts 115 aredisposed between shelves 105, 110; the threaded lower ends of eachsupport post 115 are engaged within threaded apertures defined in theshelves 105, 110, and the support collars 500 disposed on the upper endsof each support post 115 provide additional support for the shelf 105thereabove. As also shown, multiple support posts 120 are disposedbetween the topmost shelf 105 and the shelf 105 immediately therebelow;the threaded lower ends 600 of each support post 120 are engaged withinthreaded apertures defined in the shelf 105, and the dowel pin mounts610 of the upper ends of the support posts 120 receive locking pins 215therethrough. The locking pins 215 may receive one or more retainingwires 220 therethrough, as described above.

While the rack 100 is depicted in FIGS. 1A, 1B, 7, and 8 as havingrectangular shelves 105, 110 separated by support posts disposed at eachcorner, other shapes and configurations are within the scope of thepresent invention. For example, the shelves 105, 110 may be circular orhave any polygonal shape, and two, three, four, or even more supportposts may be disposed between the shelves along the perimeters thereof.FIG. 9 depicts an exemplary embodiment of a rack 100 incorporatingcircular perforated shelves 105, 110. In addition to various aspectsdetailed above, rack 100 of FIG. 9 incorporates a base 900 on which thebottom shelf 110 is disposed. In various embodiments, a shelf support1000 (not visible in FIG. 9; see FIGS. 10 and 12A) may be disposedbetween the shelf 110 and the base 900. FIG. 10 is a bottom view of therack 100 of FIG. 9 illustrating the base 900, the shelf 110, and theshelf support 1000 therebetween. The rack 100 may also include one ormore center support tubes and support brackets, as shown in more detailfor rack 1300 in FIG. 13B.

FIGS. 11A and 11B depict the base 900 in greater detail. Base 900 mayinclude or consist essentially of a collection of cross bars and throughrods that form a mesh-like “grating” structure through which gases inthe processing chamber may flow freely and space the shelf 110 (and/orthe shelf support 1000) away from the floor of the processing chamber.In the embodiment depicted in FIGS. 11A and 11B, the base includes orconsists essentially of a series of cross bars 1100 held together by aseries of through rods 1105 that extend through apertures defined withinthe cross bars 1100. As also shown in FIG. 9, the cross bars 1100 may besubstantially flat and rectangular, and the through rods 1105 may besubstantially cylindrical. The cross bars 1100 and/or the through rods1105 may have various different lengths, and, as shown in FIG. 11A,these elements may, when assembled, provide the base 900 with a size andshape approximately equal to that of one of the shelves 105, 110 (e.g.,approximately circular). That is, a lateral dimension (e.g., diameter)1110 of the base 900 may be approximately equal to a lateral dimension(e.g., diameter) 1115 of the base 900 perpendicular to dimension 1110.

In order to maintain a consistent spacing between various ones of thecross bars 1100, a series of hollow spacers 1120 may be disposed betweenthe cross bars 1100, and the through rods 1105 may extend through thespacers 1120. The spacers 1120 may have diameters (or other lateraldimensions) larger than those of the apertures defined by cross bars1100 through which the through rods 1105 extend, thereby preventingmovement of the spacers 1120 through the apertures and alteration ofspacings between various cross bars 1100. As shown in FIGS. 11A and 11B,the through rods 1105 may be fastened to the cross bars 1100 via aseries of threaded nuts 1125 and washers 1130. In addition, the base mayincorporate one or more alignment brackets 1135 incorporated within orattached to one or more of the cross bars 1100. As shown, the alignmentbrackets 1135 may be attached to one or more of the outermost cross bars1100 via one or more rivets 1140. The alignment brackets 1135 mayprotrude upward from the base 900 and interface with one or morecomplementary features in shelf support 1000 and/or the shelf 110. Forexample, the protruding portion of an alignment bracket 1135 may extendinto a bracket within shelf support 1000 (as described in further detailbelow), and/or the alignment bracket 1135 may define one or more notcheswithin which a protruding feature from shelf support 1000 or shelf 110may fit.

In various embodiments, one or more of the components of base 900 (e.g.,cross bars 1100, through rods 1105, spacers 1120, nuts 1125, washers1130, alignment brackets 1135, and/or rivets 1140) include, consistessentially of, or consist of one or more TZM alloys. In otherembodiments, one or more of the components of base 900 include, consistessentially of, or consist of one or more refractory metals, e.g., Nb,Ta, Re, W, and/or Mo. In various embodiments, one or more of thecomponents of base 900 incorporate one or more alloying elements, forexample La, at concentrations of, e.g., approximately 0.01% toapproximately 1%.

As mentioned above, a shelf support 1000 may be disposed between base900 and shelf 110. The shelf support 1000 may, for example, provideadditional support to shelf 110 and all of the other parts of theapparatus thereover. The shelf support 1000 may even provide additionalspace between base 900 and shelf 110 for the flow of process gas throughthe apparatus. FIG. 12A depicts an exemplary shelf support 1000 inaccordance with embodiments of the present invention. In the illustratedexemplary embodiment, the shelf support 1000 includes or consistsessentially of a shelf ring 1200 and a series of cross braces 1205 thatstabilize the shelf ring 1200 against deformation or twisting. The shelfring 1200 may have a size and shape (e.g., perimeter shape) thatapproximate that of base 900 and/or shelf 110. For example, as shown inFIG. 12A, the shelf support 1000 may be substantially circular and mayhave a diameter approximately equal to or less than that of base 900and/or shelf 110. The shelf ring 1200 may be fabricated (e.g., cast orwrought) in its final (e.g., circular) shape, or the shelf ring 1200 maybegin as substantially straight and deformed such that the ends of shelfring 1200 come together to make a closed shape. In other embodiments,the shelf ring 1200 may initially be multiple discrete parts with theirends brought together to form the closed shape. In such embodiments, theends of shelf ring 1200 (or its component pieces) may be fastenedtogether via one or more fasteners such as joining strips 1210 that maybe attached to the shelf ring 1200 via, e.g., one or more rivets. Asshown in FIG. 12A, various ones of the cross braces 1205 may also befastened together via, e.g., one or more rivets 1215.

FIGS. 12B and 12C depict features that may be present in exemplary shelfsupports 1000 in accordance with embodiments of the present invention.FIG. 12B, corresponding to circled area C in FIG. 12A, depicts a bracket1220 fastened to the shelf ring 1200 via one or more rivets 1225. Asshown in FIG. 12A, the shelf support 1000 may incorporate one or moresuch brackets 1220 along the perimeter of shelf ring 1200. In variousembodiments, each bracket 1220 is sized and shaped to receive analignment bracket 1135 protruding from base 900, thereby facilitatingalignment of the base 900 with the shelf support 1000. As also shown inFIG. 12B, various ones of the cross braces 1205 may extend throughapertures defined by the shelf ring 1200 and held in place via retainingwires 1230 that may each extend through a cross brace 1205 and/or bewrapped around a cross brace 1205 to prevent retraction of the crossbrace 1205 back through the shelf ring 1200. As shown in FIG. 12C,corresponding to the circled area D in FIG. 12A, various ones of thecross braces 1205 may be fastened together via, e.g., one or morethreaded studs (e.g., double-ended threaded studs) 1235 and one or morecomplementarily threaded nuts 1240.

In various embodiments, one or more of the components of shelf support1000 (e.g., shelf ring 1200, cross braces 1205, joining strips 1210,rivets 1215, brackets 1220, rivets 1225, retaining wires 1230, studs1235, and/or nuts 1240) include, consist essentially of, or consist ofone or more TZM alloys. In other embodiments, one or more of thecomponents of shelf support 1000 include, consist essentially of, orconsist of one or more refractory metals, e.g., Nb, Ta, Re, W, and/orMo. In various embodiments, one or more of the components of shelfsupport 1000 incorporate one or more alloying elements, for example La,at concentrations of, e.g., approximately 0.01% to approximately 1%.

FIGS. 13A and 13B depict an exemplary rack 1300 in accordance withvarious embodiments of the invention. As shown, the rack 1300 includesshelves 105, 110, a base 900, and a shelf support 1000. The rack 1300also includes a series of support rods 1305 between each pair ofshelves, as well as a support tube 1310 or 1315 and a support bracket1320 between each pair of shelves. The shelves of rack 1300 (or rack100) may also incorporate one or more lift hooks 1325 that enable themodularized movement or removal of a “modular unit” of rack 1300 thatmay include or consist essentially of a single shelf and all of thesupport rods 1305 connected thereto (e.g., extending downwardtherefrom). FIG. 13C depicts one such modular unit of rack 1300, andFIG. 13D depicts a section of FIG. 13C along the line denoted as E-E.

FIG. 13E, corresponding to the circled area F in FIG. 13D, is anenlarged view of an exemplary connection between a support rod 1305 anda shelf 105. As shown, an upper end of support rod 1305 extends throughan aperture defined in shelf 105, defines a shoulder 1330 to helpsupport the weight of the shelf 105 (and any workpieces thereon), andends in a threaded end 1335. The support rod 1305 may be held in placevia attachment of a nut 1340 having threads complementary to those ofthreaded end 1335. The nut 1340 may also define within its top surface arecess 1345, which may be tapered, for receiving the bottom end of asupport rod 1305 connected to a shelf 105 thereabove. FIG. 13F,corresponding to circled area G in FIG. 13D, depicts an end 1350 ofsupport rod 1305 that may be sized and shaped (e.g., tapered) to fitsnugly within the recess 1345 of a nut 1340 disposed below the rod 1305.As shown in FIGS. 13A and 13B, the ends 1350 of support rods may simplyfit within apertures (which may themselves be tapered) within thebottommost shelf 110 of rack 1300.

FIGS. 13G and 13H depict an exemplary support tube 1310 in accordancewith various embodiments of the invention. As shown in FIG. 13B, thebottom portion of support tube 1310 extends through an aperture in shelf110, and one or more recesses 1355 accommodate various ones of the crossbraces 1205 of the shelf support 1000. Thus, a depth 1360 of recesses1355 may be approximately equal to or greater than a height of suchcross braces 1205. As shown in FIG. 13G, the top portion of support tube1310 may define therewithin a set of recesses 1365 that accommodate atleast a portion of the thickness of the support bracket 1320. In thismanner, the support tube 1310 and support bracket 1320 help support theweight of the shelf 105 thereover (and any workpieces thereon). As shownin FIG. 13H, the support tube 1310 may include or consist essentially oftwo interfitting U-channel beams 1370 fastened together by, e.g., one ormore rivets 1375. In other embodiments, the support tube 1310 may becomposed of a single cylindrical part. In various embodiments, supporttube 1310 may have a cross-sectional shape that is substantially thesame as that of the large apertures within the shelves 105, 110 throughwhich the support tubes partially extend. For example, the support tubemay have a substantially square cross-sectional shape, as shown in FIG.13H, or the cross-sectional shape may be rectangular, circular, etc.

FIGS. 13I and 13J depict an exemplary support tube 1315 in accordancewith various embodiments of the invention. As shown in FIG. 13B, thebottom portion of support tube 1315 extends through an aperture in ashelf 105, and one or more recesses 1380 accommodate at least a portionof the support bracket 1320 disposed below that shelf 105. As shown inFIG. 13I, the top portion of support tube 1315 may define therewithin aset of recesses 1385 that accommodate at least a portion of thethickness of a support bracket 1320. In this manner, the support tube1315 and support bracket 1320 help support the weight of the shelf 105thereover (and any workpieces thereon). As shown in FIG. 13J, thesupport tube 1315 may include or consist essentially of two interfittingU-channel beams 1390 fastened together by, e.g., one or more rivets1395. In other embodiments, the support tube 1315 may be composed of asingle cylindrical part. In various embodiments, support tube 1315 mayhave a cross-sectional shape that is substantially the same as that ofthe large apertures within the shelves 105 through which the supporttubes partially extend. For example, the support tube may have asubstantially square cross-sectional shape, as shown in FIG. 13J, or thecross-sectional shape may be rectangular, circular, etc.

FIG. 13K depicts an exemplary support bracket 1320 in accordance withvarious embodiments of the present invention. As shown, the supportbracket 1320 may include or consist essentially of multiple anglebrackets 1397 fastened together with, e.g., one or more rivets 1399,that collectively form a cross shape. In other embodiments, the supportbracket 1320 may be composed of a single part having the desired shape.

In various embodiments, one or more of the components of rack 1300(e.g., shelves 105, 110, base 900, shelf support 1000, rods 1305,support tubes 1310, 1315, support brackets 1320, lift hooks 1325, nuts1340, and/or rivets 1375, 1395, 1399) include, consist essentially of,or consist of one or more TZM alloys. In other embodiments, one or moreof the components of rack 1300 include, consist essentially of, orconsist of one or more refractory metals, e.g., Nb, Ta, Re, W, and/orMo. In various embodiments, one or more of the components of rack 1300incorporate one or more alloying elements, for example La, atconcentrations of, e.g., approximately 0.01% to approximately 1%.

As mentioned above, racks 100, 1300 in accordance with embodiments ofthe present invention may be utilized to receive and support parts (or“components”) during high-temperature processes such as brazing. Forexample, multiple heavy metallic parts may be placed on each shelf 105,110 with a brazing material placed at locations between the parts wherebrazed joints are desired. For example, a first component including,consisting essentially of, or consisting of steel (e.g., stainlesssteel) may be joined to a second component including, consistingessentially of, or consisting of Ti with a brazing material including,consisting essentially of, or consisting of, for example, silver or analloy of nickel and chromium. The rack 100, 1300 may be disposed withina furnace chamber configured to heat the parts and the rack 100, 1300 toelevated processing temperatures of greater than 1000° C., e.g., betweenapproximately 1100° C. and approximately 1500° C. or even approximately2000° C. with appropriate refractory metal selection. The furnacechamber may be sealable to enable the evacuation thereof for processingparts under vacuum (for example, to prevent exposure to oxygen at hightemperatures and resulting deleterious oxidation) or for theintroduction of one or more process gases, e.g., hydrogen gas if areducing atmosphere is desired. The parts are heated within the furnacechamber at the desired processing temperature and under the desiredambient conditions until the brazing material melts and forms the brazedjoint(s) between the parts. The parts may then be cooled down andremoved from the rack 100, 1300 and the furnace chamber for furtherprocessing. The design features of rack 100, 1300 described hereinadvantageously enable the high-temperature batch processing of multiplejoined parts and repeated use without deformation or failure of rack100, 1300.

Thus, as shown in FIG. 14, embodiments of the invention include ahigh-temperature brazing process 1400. In a step 1405, a rack 100 and/ora rack 1300 may be disposed within a furnace chamber. In a step 1410,multiple components to be brazed together may be placed on one or moreof the shelves of the rack, and brazing material is disposed betweencomponents in locations where it is desired to join components viabrazed joints. The components may each include, consist essentially of,or consist of, for example, steel and/or Ti. The brazing material mayinclude, consist essentially of, or consist of, for example, silver,nickel, and/or chromium. In a step 1415, a processing ambient may beintroduced within the furnace chamber. The processing ambient mayinclude, consist essentially of, or consist of, for example, vacuum, oneor more inert gases (e.g., argon), nitrogen, and/or hydrogen. Theprocessing ambient may be substantially free of oxygen to preventoxidation of the brazed joint. In a step 1420, the furnace chamber maybe heated to a process temperature, e.g., a temperature exceedingapproximately 1000° C., thereby melting the brazing material. Thebrazing material thus forms joints between various ones of thecomponents. In a step 1425, the temperature within the furnace chamberis reduced, and the brazed parts are removed from the rack and thefurnace chamber. In various embodiments of the invention, various stepsof process 1400 may be omitted or performed in a different order thanthat presented in FIG. 14.

The terms and expressions employed herein are used as terms andexpressions of description and not of limitation, and there is nointention, in the use of such terms and expressions, of excluding anyequivalents of the features shown and described or portions thereof. Inaddition, having described certain embodiments of the invention, it willbe apparent to those of ordinary skill in the art that other embodimentsincorporating the concepts disclosed herein may be used withoutdeparting from the spirit and scope of the invention. Accordingly, thedescribed embodiments are to be considered in all respects as onlyillustrative and not restrictive.

What is claimed is: 1.-35. (canceled)
 36. An apparatus for receiving andsupporting one or more components during processing thereof at a processtemperature greater than approximately 1000° C., the apparatuscomprising: a first shelf comprising a first refractory metal having amelting point greater than the process temperature; and disposed beneaththe first shelf, a base comprising (i) a plurality of spaced-apart crossbars each (a) defining a plurality of apertures therethrough and (b)comprising a second refractory metal having a melting point greater thanthe process temperature, and (ii) a plurality of spaced-apart throughrods each (a) extending through the apertures of multiple ones of thecross bars and (b) comprising a third refractory metal having a meltingpoint greater than the process temperature.
 37. The apparatus of claim36, wherein the first shelf comprises one or more first lift hooksextending therefrom, the first shelf being separable from the base via alifting force applied via the one or more first lift hooks.
 38. Theapparatus of claim 36, wherein the base comprises one or more alignmentfeatures extending upward therefrom.
 39. The apparatus of claim 36,further comprising, disposed over the first shelf, a second shelfcomprising a fourth refractory metal having a melting point greater thanthe process temperature.
 40. The apparatus of claim 39, furthercomprising: a first support tube (i) having an upper end and a lower endopposite the upper end, (ii) comprising a fifth refractory metal havinga melting point greater than the process temperature, and (iii)configured to extend from the first shelf to the second shelf, whereinthe upper end of the first support tube defines therein a plurality ofnotches; and a support brace comprising a plurality of appendages forsupporting the second shelf thereon, each appendage being configured forreceipt into one of the notches of the upper end of the first supporttube.
 41. The apparatus of claim 40, wherein: the first shelf defines acentral aperture therethrough; and the lower end of the first supporttube is configured to extend through the central aperture of the firstshelf.
 42. The apparatus of claim 39, further comprising: a plurality offirst support posts, each first support post (i) comprising a fifthrefractory metal having a melting point greater than the processtemperature, (ii) configured to extend between the first shelf and thesecond shelf, and (iii) having an upper end and a lower end opposite theupper end, wherein (i) the second shelf comprises one or more secondlift hooks extending therefrom, and (ii) the second shelf and the firstsupport posts are collectively separable, as a modular unit, from thefirst shelf via a lifting force applied via the one or more second lifthooks.
 43. The apparatus of claim 42, wherein the first shelf definestherein a plurality of apertures, the lower end of each first supportpost being configured to be received within one of the apertures. 44.The apparatus of claim 43, wherein the lower end of each first supportpost is tapered.
 45. The apparatus of claim 42, wherein the upper end ofeach of the first support posts is threaded.
 46. The apparatus of claim42, wherein: the second shelf defines a plurality of apertures definedtherethrough; and each of the first support posts defines a supportcollar proximate the upper end, a lateral dimension of the first supportpost above the support collar being smaller than a lateral dimension ofthe first support post below the support collar, whereby, when an upperend of a first support post is received in an aperture of the secondshelf, a portion of the second shelf proximate the aperture rests uponthe support collar of the first support post received in the aperture.47. The apparatus of claim 42, wherein the second shelf defines aplurality of apertures defined therethrough; and the upper end of eachof the first support posts is configured to protrude through one of theapertures.
 48. The apparatus of claim 47, further comprising a pluralityof first nuts, each first nut (i) comprising a sixth refractory metalhaving a melting point greater than the process temperature, and (ii)being configured to engage with the upper end of one of the firstsupport posts to thereby secure the one of the first support posts tothe second shelf.
 49. The apparatus of claim 48, wherein each first nutdefines therein a lower aperture, at least a portion of the loweraperture being threaded for engagement with the upper end of one of thefirst support posts.
 50. The apparatus of claim 49, wherein each firstnut defines therein an upper aperture.
 51. The apparatus of claim 50,wherein at least a portion of the upper aperture is tapered.
 52. Theapparatus of claim 50, further comprising: a third shelf comprising anseventh refractory metal having a melting point greater than the processtemperature; and a plurality of second support posts, each secondsupport post (i) comprising a eighth refractory metal having a meltingpoint greater than the process temperature, (ii) configured to extendbetween the second shelf and the third shelf, (iii) having an upper end,and (iv) having a lower end, opposite the upper end, for engagement withan upper aperture of one of the first nuts.
 53. The apparatus of claim36, further comprising a shelf support disposed between the first shelfand the base, the shelf support comprising a fourth refractory metalhaving a melting point greater than the process temperature.
 54. Amethod of high-temperature brazing at a process temperature greater thanapproximately 1000° C., the method comprising: disposing within afurnace chamber an apparatus comprising: a first shelf comprising afirst refractory metal having a melting point greater than the processtemperature, and disposed beneath the first shelf, a base comprising (i)a plurality of spaced-apart cross bars each (a) defining a plurality ofapertures therethrough and (b) comprising a second refractory metalhaving a melting point greater than the process temperature, and (ii) aplurality of spaced-apart through rods each (a) extending through theapertures of multiple ones of the cross bars and (b) comprising a thirdrefractory metal having a melting point greater than the processtemperature; disposing on the first shelf of the apparatus (i) a firstcomponent, (ii) a second component, and (iii) a brazing materialdisposed between the first and second components; introducing within thefurnace chamber a processing ambient; and applying the processtemperature within the furnace chamber, thereby melting the brazingmaterial and joining the first and second components at a brazed jointtherebetween.
 55. The method of claim 54, wherein introducing theprocessing ambient comprises at least partially evacuating the furnacechamber.
 56. The method of claim 54, wherein introducing the processingambient comprises introducing a process gas within the furnace chamber.57. The method of claim 56, wherein the process gas comprises hydrogen.